Water encoding for vision systems

ABSTRACT

Technologically improved vision systems and methods that provide enhanced water encoding are provided. The vision system receives terrain data from a terrain database and aircraft state data from a navigation system. The vision system commands a display system to display a map image that is reflective of a view from a current location of the platform. The vision system processes terrain data and aircraft state data to identify a water feature, determine a distance between the platform and the water feature, and determine a textural representation for the water feature. The textural representation comprises a symbol and an associated symbol pattern. The vision system commands a display system to overlay, on the map image, the water feature with the textural representation.

TECHNICAL FIELD

The present invention generally relates to mobile platform visionsystems, and more particularly relates to water encoding for visionsystems.

BACKGROUND

Generally, vision systems comprise head down displays and head updisplays. In a synthetic vision system (SVS) head down display (HDD),land, water, and sky are represented by distinctly different colors foreasy pilot distinction and situation awareness. In an enhanced visionsystem, Infrared images represent thermal signature of forward field ofview, and may or may not provide distinction of water and land areas viaperceived intensity. In a combined vision system (CVS) HDD, an SVS imageand an EVS image are combined into one image. In the CVS HDD image, anEVS video insert section is may be colored by the backgroundland/water/sky colors of the SVS image.

In contrast to the HDD, a head mounted display (HMD), near to eyedisplay (NTE), and a head up display (HUD) must be useable over a widerange of ambient light conditions and display is typically of singlecolor. Therefore, using intensity to differentiate between water, land,and sky can be ineffective on a HUD, particularly in bright ambientconditions. Displaying SVS images and/or CVS images in a typicalmono-color using color intensity to differentiate between water, land,and sky, may be especially ineffective.

Accordingly, improvements to vision systems and methods are desirable.Specifically, technologically improved systems and methods that provideenhanced water encoding and supports a wide variety of vision systemsare desirable. Furthermore, other desirable features and characteristicsof the present disclosure will become apparent from the subsequentDetailed Description and the appended claims, taken in conjunction withthe accompanying drawings and this Background.

BRIEF SUMMARY

This summary is provided to describe select concepts in a simplifiedform that are further described in the Detailed Description. Thissummary is not intended to identify key or essential features of theclaimed subject matter, nor is it intended to be used as an aid indetermining the scope of the claimed subject matter.

A method for a vision system in a platform is provided. The methodcomprising: at a control module, receiving terrain data from a terraindatabase; receiving aircraft state data from a navigation system;displaying, on a display system, an image that is reflective of a viewfrom a current location of the platform; processing the terrain data andthe aircraft state data to (i) identify a water feature, and (ii)determine a textural representation for the water feature; andtexturizing the water feature by overlaying, on the image, the waterfeature with the textural representation.

Also provided is a vision system, comprising: a navigation system; adisplay system; a terrain database; and a control module operationallycoupled to the navigation system, the display system, and the terraindatabase, the control module configured to: receive terrain data fromthe terrain database; receive aircraft state data from the navigationsystem; display, on the display system, a map image that is reflectiveof a view from a current location of the platform; process the terraindata and the aircraft state data to (i) identify a water feature, and(ii) determine a textural representation for the water feature; andtexturize the water feature by overlaying, on the map image, the waterfeature with the textural representation.

A control module for use in a combined vision system (CVS) on anaircraft having a navigation system is provided. The control modulecomprising: a memory comprising terrain data; and a processoroperationally coupled to the memory and configured to process terraindata and aircraft state data to: generate display commands for a displaysystem to generate a map image that is reflective of a view from acurrent location of the aircraft; identify a water feature; anddetermine a textural representation for the water feature.

Furthermore, other desirable features and characteristics of the systemand method will become apparent from the subsequent detailed descriptionand the appended claims, taken in conjunction with the accompanyingdrawings and the preceding background.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe following drawing figures, wherein like numerals denote likeelements, and

FIG. 1 is a block diagram of an enhanced vision system, in accordancewith an exemplary embodiment;

FIG. 2 is a block diagram of the control module of FIG. 1, in accordancewith an exemplary embodiment;

FIG. 3 is sketch illustrating water encoding in a combined vision system(CVS), in accordance with an exemplary embodiment;

FIG. 4 is a long range image from a head up display (HUD), in accordancewith an exemplary embodiment;

FIG. 5 is a head up display (HUD) image showing natural landmarks, inaccordance with an exemplary embodiment; and

FIG. 6 is a short range image from a head up display (HUD), inaccordance with an exemplary embodiment; and

FIG. 7 is a flow chart for a method for water encoding, in accordancewith an exemplary embodiment.

DETAILED DESCRIPTION

The following detailed description is merely illustrative in nature andis not intended to limit the embodiments of the subject matter or theapplication and uses of such embodiments. As used herein, the word“exemplary” means “serving as an example, instance, or illustration.”Thus, any embodiment described herein as “exemplary” is not necessarilyto be construed as preferred or advantageous over other embodiments. Allof the embodiments described herein are exemplary embodiments providedto enable persons skilled in the art to make or use the invention andnot to limit the scope of the invention that is defined by the claims.Furthermore, there is no intention to be bound by any theory presentedin the preceding background or the following detailed description.

As used herein, the term module refers to any hardware, software,firmware, electronic control component, processing logic, and/orprocessor device, individually or in any combination, including withoutlimitation: application specific integrated circuit (ASIC), anelectronic circuit, a processor (shared, dedicated, or group) and memorythat executes one or more software or firmware programs, a combinationallogic circuit, and/or other suitable components that provide thedescribed functionality. The provided system and method may take theform of a control module (FIG. 1, 104), and may be separate from, orintegrated within, a preexisting mobile platform management system,avionics system, or aircraft flight management system (FMS).

Exemplary embodiments of the disclosed vision system 102 and controlmodule (FIG. 1, 104) effectively texturize a water feature bydetermining a textural representation for the water feature, andcommanding a display system (FIG. 1, 30) to overlay a map image with thetextural representation. The selected symbol and symbol pattern may berelated to a distance between the aircraft 100 the water feature; and,the selected symbol and symbol pattern may change as the aircraft 100crosses one or more range boundaries of distance from the water feature.With the herein described texturizing of the water feature(s), and someof the additional features described below, the control module 104delivers a technological improvement over conventional vision systemsthat require an undue workload to distinguish water from land,particularly in monochrome applications and across a range of ambientlighting conditions. These features and additional functionality aredescribed in more detail below.

Turning now to FIG. 1, in the provided examples, the platform 100 is anaircraft, and may be referred to as aircraft 100. In the describedembodiments, a control module 104 is generally realized as commanding atechnologically enhanced vision system 102 (also referred to as “waterencoding system” 102, and “system” 102) within the aircraft 100. In thedescribed embodiments, the control module 104 and vision system 102 arewithin the aircraft 100; however, the concepts presented herein can bedeployed in a variety of mobile platforms, spacecraft, and the like.Accordingly, in various embodiments, the control module 104 may resideelsewhere and/or enhance part of larger avionics management system, orplatform management system. Further, it will be appreciated that thesystem 102 may differ from the embodiment depicted in FIG. 1. Forexample, aspects of the user input device 34, display system 30, andgraphics system 32 may form a control display unit (CDU) used forcommand and control of the FMS 106.

The control module 104 may be operationally coupled to: a FlightManagement System (FMS) 106, a user interface 108 (which may compriseone or more of a display system 30, a graphics system 32, and a userinput device 34), an on-board sensor system 110, and a terrain database114. The operation of these functional blocks is described in moredetail below.

The depicted FMS 106 provides a flight plan and a destination runway foran intended landing. As depicted, the FMS 106 is a functional block thatcomprises a navigation system 20 and a navigation database 22, and maytherefore provide position determination data retrieved from sensorcomponents in the navigation system 20 The navigation system 20comprises sensors for determining instantaneous current position for theaircraft 100. The instantaneous current position of a platform oraircraft 100 may be referred to as aircraft state data, and/or positiondetermining data, and comprises the current latitude, longitude,heading, and the current altitude (or above ground level) for theaircraft 100. The means for ascertaining current or instantaneousaircraft state data for the aircraft 100 may be realized, in variousembodiments, as a global positioning system (GPS), inertial referencesystem (IRS), or a radio-based navigation system (e.g., VHFOmni-directional radio range (VOR) or long range aid to navigation(LORAN)), and may include one or more navigational radios or othersensors suitably configured to support operation of the navigationsystem 20, as will be appreciated in the art. Under direction of theprogram 162 (see FIG. 2), the control module 104 may process navigationdata to determine an aircraft instantaneous position with respect to aflight plan and guide the aircraft along the flight plan. The controlmodule 104 may also process the flight plan and position determiningdata to determine a current phase of flight.

The navigation database 22 may comprise waypoint information, airportfeatures information, runway position and location data, holdingpatterns, flight procedures, approach procedures, and various flightplanning and distance measuring rules and parameters. The FMS 106 isconfigured to provide guidance, such as lateral navigation (LNAV) andvertical navigation (VNAV), to a crew, based on processing the aircraftstate data with information within the navigation database 22. As usedherein, “navigation data” may comprise data and information from thenavigation system 20 and/or the navigation database 22, such as, but notlimited to, aircraft state data and current phase of flight information.

A user interface 108 is coupled to the control module 104, andcooperatively configured to allow a user (e.g., a pilot, co-pilot, orcrew member) to interact with the display system 30, the FMS 106, and/orother elements of the system 102 in a conventional manner. The userinterface 108 comprises one or more systems (display system 30, agraphics system 32, and a user input device 34) described below.

In general, the display system 30 may include any device or apparatussuitable for displaying (also referred to as rendering) flightinformation or other data associated with operation of the aircraft in aformat viewable by a user. The display devices may provide threedimensional or two dimensional map images, and may further providesynthetic vision imaging. Accordingly, a display device responds to arespective communication protocol that is either two-dimensional orthree, and may support the overlay of text, alphanumeric information, orvisual symbology on a given map image. Non-limiting examples of suchdisplay devices include cathode ray tube (CRT) displays, and flat paneldisplays such as LCD (liquid crystal displays) and TFT (thin filmtransistor) displays. In practice, the display system 30 may be part of,or include, a primary flight display (PFD) system, a multi-functiondisplay (MFD), a panel-mounted head down display (HDD), a head updisplay (HUD), or a head mounted display system, such as a “near to eyedisplay” system. With respect to the present embodiments, focus will beon the head up display (HUD).

The renderings of the display system 30 may be processed, at least inpart, by the graphics system 32. Display methods include various typesof computer generated symbols, text, and graphic informationrepresenting, for example, pitch, heading, flight path, airspeed,altitude, runway information, waypoints, targets, obstacle, terrain, andrequired navigation performance (RNP) data in an integrated, multi-coloror monochrome form. In some embodiments, the graphics system 32 may beintegrated within the control module 104; in other embodiments, thegraphics system 32 may be integrated within the display system 30.Regardless of the state of integration of these subsystems, responsiveto receiving display commands from the control module 104, the displaysystem 30 displays, renders, or otherwise visually conveys, one or moregraphical representations or images associated with operation of theaircraft 100, as described in greater detail below. In variousembodiments, images displayed on the display system 30 may also beresponsive to processed user input that was received via a user inputdevice 34.

The user input device 34 may include any one, or combination, of variousknown user input device devices including, but not limited to: a touchsensitive screen; a cursor control device (CCD) (not shown), such as amouse, a trackball, or joystick; a keyboard; one or more buttons,switches, or knobs; a voice input system; and a gesture recognitionsystem. Non-limiting examples of uses for the user input device 34include: entering values for stored variables 164, loading or updatinginstructions and applications 160, loading and updating program 162, andloading and updating the contents of the database 156, each described inmore detail below. In addition, pilots or crew may enter flight plans,Standard Operating Procedures (SOP), and the like, via the user inputdevice 34. In embodiments using a touch sensitive screen, the user inputdevice 34 may be integrated with a display device in display system 30.

The on-board sensor system 110 comprises a variety of different sensors,each directed to sensing a respective different system of the aircraft100 while in flight. Non-limiting examples of sensors include: winddirection and velocity sensors, fuel-level sensors, engine temperaturesensors, humidity sensors, cabin sensor sensors, and other system statussensors. In addition to sensing aircraft 100 systems while in flight,some of the on-board sensors are externally focused, and provideenvironmental and terrain information. Real-time aircraft sensor data,therefore, includes real-time local weather data and infra-red senseddata, as expected for use in an enhanced vision system (EVS), inaddition to, aircraft system data.

The terrain database 114 comprises environmental features informationrelevant to a travel path that the aircraft 100 will take. Non-limitingexamples of terrain data from the terrain database includes sizes,shapes, areas, locations (latitude, longitude, feet above sea level),and boundaries between land, air, and water features. The terrain datamay be pre-loaded into the terrain database 114, and then selectivelytransferred to memory 152 during execution of algorithms for texturizingthe water features embodied in program 162. In other embodiments, theterrain data is already included in the control module 104, such as indatabase 156.

The control module 104 processes input from the operationally coupledcomponents and performs the functions of: range determining 40, andtexture determining 42. The control module 104 and its functions arefurther described in connection with FIG. 2, as follows.

The control module 104 includes an interface 154, communicativelycoupled to a processor 150 and memory 152 (via a bus 155), database 156,and an optional storage disk 158. The processor 150 may comprise anytype of processor or multiple processors, single integrated circuitssuch as a microprocessor, or any suitable number of integrated circuitdevices and/or circuit boards working in cooperation to carry out thedescribed operations, tasks, and functions by manipulating electricalsignals representing data bits at memory locations in the system memory,as well as other processing of signals.

The memory 152, the navigation database 22, the terrain database 114,the database 156, and optional disk 158 maintain data bits and may beutilized by the processor 150 as both storage and a scratch pad. Thememory locations where data bits are maintained are physical locationsthat have particular electrical, magnetic, optical, or organicproperties corresponding to the data bits. The memory 152 can be anytype of suitable computer readable storage medium. For example, thememory 152 may include various types of dynamic random access memory(DRAM) such as SDRAM, the various types of static RAM (SRAM), and thevarious types of non-volatile memory (PROM, EPROM, and flash). Incertain examples, the memory 152 is located on and/or co-located on thesame computer chip as the processor 150. In the depicted embodiment, thememory 152 stores the above-referenced instructions and applications 160along with one or more configurable variables in stored variables 164.The database 156 and the disk 158 are computer readable storage media inthe form of any suitable type of storage apparatus, including directaccess storage devices such as hard disk drives, flash systems, floppydisk drives and optical disk drives. The database 156 may include anairport database (comprising airport features) and a terrain database(comprising terrain features), parameters and instructions for runwaydetection and selection, and parameters and instructions for generatingalerts as described herein. In combination, the features from theairport database and the terrain database are referred to as mapfeatures. Information in the database 156 and memory 152 may beorganized and/or imported from an external source 130, or by programmingvia the user input device 34, during an initialization step of a process(see initialization 702 FIG. 7).

The bus 155 serves to transmit programs, data, status and otherinformation or signals between the various components of the controlmodule 104. The bus 155 can be any suitable physical or logical means ofconnecting computer systems and components. This includes, but is notlimited to, direct hard-wired connections, fiber optics, infrared andwireless bus technologies.

The interface 154 enables communications within the control module 104,can include one or more network interfaces to communicate with othersystems or components, and can be implemented using any suitable methodand apparatus. For example, the interface 154 enables communication froma system driver and/or another computer system. In one embodiment, theinterface 154 obtains data from external data source(s) 130 directly.The interface 154 may also include one or more network interfaces tocommunicate with technicians, and/or one or more storage interfacessupporting direct connections with storage apparatuses, such as thedatabase 156.

During operation, the processor 150 loads and executes one or moreprograms, algorithms and rules embodied as instructions and applications160 contained within the memory 152 and, as such, controls the generaloperation of the control module 104 as well as the system 102. Inexecuting the process described herein, such as the method 700 of FIG.7, the processor 150 specifically loads and executes the instructionsand models embodied in the novel program 162. Within the control module104, the processor 150 and the memory 152 form a processing engineperforming processing activities, data conversion, and data translationthat result in the functions of the control module 104, as is describedin more detail below. The control module 104 may perform its functionsin accordance with steps of a method (FIG. 7, method 700).

Additionally, the processor 150 is configured to, in accordance with theprogram 162: process received inputs (selectively, any combination ofinput from the set including: the FMS 106, the user interface 108, theon-board sensor system 110, the input/output (I/O) system 112, andexternal sources 130); reference any of the databases (such as, theterrain database 114, the navigation database 22, and the database 156);and, generate commands that command and control the user interface 108(specifically, the display system 30).

Generally, the control module 104 determines a textural representationfor a water feature, and commands the display system 30 to overlay thetextural representation on the synthetic vision system (SVS) map image.This is also referred to as “texturizing the water.” In FIG. 3, sketch300 represents this concept in a combined vision system (CVS) imagehaving an SVS image overlaid with an EVS image 302. The SVS waterboundary 304 is shown below a zero pitch reference line ZPRL 306. In theEVS image 302, the water boundary is 310. The textural representationused for the water feature comprises a symbol 308 that is repeatedthroughout the water feature, within the water boundaries (304, 310) ofthe water feature. The water symbol 308 may be selectively positioned ontop of EVS image for the areas within the water boundaries. Therepetition of the symbol 308 may follow a pre-arranged symbol pattern.The arrangement of symbols 308 into symbol patterns is described inconnection with FIGS. 4-6.

The water encoding system 102 commands the display system 30 to render amap image reflective of a view from the current location of the vehicle.The top of the map image is representative of features farthest awayfrom the aircraft 100, and the bottom of the map image is representativeof features nearest to the aircraft 100. Turning now to FIG. 4, aperspective view image, SVS image 400, represents a view of the terrainand environment from the platform looking forward, in the direction oftravel. At the top of the SVS image 400, the sky 456 extends downward toa boundary 452 where sky 456 meets the water feature 450, land body 402and land body 404. As the aircraft 100 travels, the SVS image 400 iscontinuously updated to reflect the aircraft 100 state data (positionand location). Boundary 452 is a virtual boundary, meaning that itrepresents the farthest extent of the displayed view from the aircraft100, rather than a real boundary between features as defined in theterrain database 114. For the purpose of the present discussion, theboundaries displayed on the map image are the boundaries used fordetermining the water feature to texturize. Accordingly, depending onthe aircraft's 100 instantaneous position and location, a given boundaryof a water feature may be real or virtual.

The control module 104 determines a textural representation for thewater feature 450. The control module 104 generates display commands forthe display system 30 to texturize the water feature 450. Responsive tothe display commands, the display system 30 texturizes the water feature450 by overlaying, on the map image (SVS image 400), the water featurewith the textural representation. Textural representations are selectedto provide enough contrast around the water texture symbols such that,when overlaid on a map image that employs coloration techniques, thetextural representations continue to be plainly visible anddistinguishable. For example, the texturized water feature 450 may beeasily brought into and rendered on a HUD CVS image.

In various embodiments, the textural representation comprises a symboland an associated symbol pattern. It is to be understood that multiplesymbols may be employed, and also multiple symbol patterns may beemployed, and each may selectively be associated with each other. Agiven symbol pattern may comprise dimensions that are responsive to oneor more of (i) water feature 450 dimensions, and (ii) a location of theaircraft 100 with respect to the water feature 450. In addition, thesymbol dimensions may be based on one or more of (i) symbol patterndimensions, (ii) water feature 450 dimensions, and (iii) a location ofthe aircraft 100 with respect to the water feature 450.

Continuing with FIG. 4, the map image of SVS image 400 depicts a symbol408 (a plus sign or cross) repeated in a symbol pattern. The firstsymbol pattern is a grid of rows and columns, each row separated fromits neighbor rows by a row space 414, and each column separated by acolumn space (a column space 410 and a column space 412) from itsneighbor columns. The symbol 408 is generally distributed in the firstsymbol pattern such that one symbol 408 occupies each intersection of arow and a column. Said differently, the symbols 408 are separated fromeach other by the row space 414 and a column space (column space 410and/or column space 412). In some textural representations, the symbolpattern has the column space 410 and the column space 412 equal. Inother textural representations, the column space 410 and the columnspace 412 are not equal. In some embodiments, columns are parallel witheach other, and perpendicular to rows. As stated earlier, multiple othersymbol patterns are supported.

Distance between the aircraft and the water feature 450 may be visuallycommunicated with the textural representation. For example, in the mapimage SVS image 400, the column spaces 410 and 412 are wider at thebottom and narrower at the top, to indicate perspective, or distancebetween the aircraft 100 and the water feature. Distance between theaircraft and the water feature 450 may also be visually communicated byaltering the textural representation based on a predeterminedconfigurable distance called a threshold range.

When a threshold range is employed, the control module 104 compares arange, or distance, between the aircraft 100 and the water feature tothe threshold range. The change from one side of the threshold range tothe other is rendered in a manner that is visually distinguishable. Forexample, when the distance between the aircraft 100 and the waterfeature 450 is less than or equal to the threshold range, one texturalrepresentation may be employed, and when the distance from the aircraft100 to the water feature 450 is greater than the threshold range, thetextural representation may be modified or another texturalrepresentation may be employed. Selectively, any combination of thesymbol and symbol pattern described above may be utilized in texturalrepresentations based on the threshold range.

To demonstrate this concept, consider the textural representationoverlaid on the map image in FIG. 4 to be an example of one texturalrepresentation, in which the distance between the aircraft 100 and thewater feature 450 is less than, or equal to, the threshold range. Whilethe plus sign of symbol 408 is readily visually distinguishable asshown, viewing the same water feature from farther away may result incrowding a plurality of symbol 408 into a small map image space, makingthem difficult to distinguish. An increase of texture density may beemployed by the control module 104 as aircraft 100 gets closer to theground to enhance ground closure perceptual cues—e.g., you first see theforest, then you see the tree and as you get closer you see treebranches and then really close you see the leaves. Comparing FIG. 4 toFIG. 5, a different textural representation is utilized when aircraft100 is farther away.

In FIG. 5, the distance of the aircraft 100 to the water feature 550 hasbeen determined to be greater than the threshold range. In FIG. 5, SVSimage 500 shows a boundary 552 separating the water feature 550 from thesky 556. Land is denoted at 502. A color intensity change is employedfor a mono-color map image of SVS 500. In FIG. 5, the texturalrepresentation utilized comprises a symbol 508 (a dot) that is visuallydistinguishable from the plus sign of symbol 408, and is more adaptableto a crowded map image. Symbol 508 is distributed in rows and columnsacross the water feature 550. In addition to employing a differentsymbol at a greater distance, column space 512 and row space 514 mayalso be visually distinguishable (i.e., different size) from row space414, column space 410 and a column space 412.

Symbols and symbol patterns are also selected to be readily visuallydistinguishable from symbols used to represent natural landmarks; anexample of this is depicted in FIG. 6. SVS image 600 depicts waterfeature 650, land 602 and sky 656. Symbols 608 are distributedthroughout the water feature 650, separated from each other by a columnspace 610 and a row space 614. Symbols and symbol patterns used for aland features, such as a landing strip 660, is shown. As is observable,symbols 608 are easily visually distinguishable from symbols used forlanding strip 660, and from other symbols, like a symbol indicating asynthetic enhanced runway extended centerline

As mentioned, the control module 104 may be used to implement a method700, as shown in the flow chart of FIG. 7. For illustrative purposes,the following description of method 700 may refer to elements mentionedabove in connection with FIG. 1 and FIG. 2. In practice, portions ofmethod 700 may be performed by different components of the describedsystem. It should be appreciated that method 700 may include any numberof additional or alternative tasks, the tasks shown in FIG. 7 need notbe performed in the illustrated order, and method 700 may beincorporated into a more comprehensive procedure or method havingadditional functionality not described in detail herein. Moreover, oneor more of the tasks shown in FIG. 7 could be omitted from an embodimentof the method 700 as long as the intended overall functionality remainsintact.

The method starts, and at 702 the control module 104 is initialized. Asmentioned above, initialization may comprise uploading or updatinginstructions and applications 160, program 162, stored variables 164,and the various lookup tables stored in the database 156. Examples ofparameters that may be stored in stored variables 164 include parametersused by the instructions and applications 160 and the program 162 (forexample, a predetermined configurable range, and values used for scalingand sizing the texture symbols and their placement in various symbolpatterns). Stored variables 164 may also include various shapes, sizes,and color rendering references for flight images, buttons and displayssuch as employed on a graphical user interface (GUI) displayed on thedisplay system 30, for seeking user input. The program 162 may alsoinclude additional instructions and rules for commanding any of avariety of the specific display devices described in connection with thedisplay system 30.

At 704, aircraft state data is received. As mentioned, aircraft statedata comprises position determining data provided via the navigationsystem 20; the aircraft state data, therefore, comprises the aircraft's100 instantaneous, real-time, position and location. At 706, terraindata is received. Terrain data may be received from the terrain database114. In some embodiments, the terrain data is already copied into memory(such as memory 152 or database 156) within the control module 104.Terrain data comprises the requisite boundaries and feature informationto distinguish the environment (i.e., distinguish between land, water,and air) along a flight path of the aircraft 100. At 708, the controlmodule 104 commands a display system 30 to render a map image that isreflective of a view from the current location of the aircraft 100. Itis to be understood that the map image comprises information about theterrain surrounding the aircraft 100. Step 708 is continuously repeated,such that the map image continuously reflects the view from the currentlocation of the aircraft 100 as it travels.

At 710, terrain data and aircraft state data are processed to identify awater feature (450, 550, and 650) in a travel path of the aircraft 100and to determine a location of the aircraft 100 with respect to thewater feature. As mentioned, a predetermined configurable thresholdrange may be employed. If not, at 712, a textural representation isdetermined for the water feature (450, 550, and 650) at 714 and thetextural representation is overlaid on the water feature on the mapimage at 716. In embodiments using a predetermined configurablethreshold the distance (between the aircraft 100 and the water feature550) to the threshold range, at 712, the method 700 proceeds to comparethe distance (between the aircraft 100 and the water feature (450, 550,650)) to the threshold range at 718. While the distance is greater thanthe threshold range, the first textural representation is determined at722 and overlaid at 724. Once the distance becomes less than thethreshold range at 720, a second textural representation is determinedat 726 and overlaid at 728. It is to be understood that when the secondtextural representation is utilized at 728, the first texturalrepresentation is removed. This is also true any time that the methoddetermines a new textural representation that utilizes a differentsymbol and/or symbol pattern. After 728 and after 724 the method may endor may return to 710.

Accordingly, the exemplary embodiments discussed above provide atechnologically improved vision system 102 that determines texturalrepresentations for water features and encodes them for use in a varietyof display systems, and specifically for systems that cannot rely oncolor intensity for land/water/sky differentiation. The embodimentsdetermine textural representations that vary responsive to a distancebetween a platform and a water feature.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention. It being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims.

What is claimed is:
 1. A method for a vision system in a platform, themethod comprising: at a control module, receiving terrain data from aterrain database; receiving aircraft state data from a navigationsystem; displaying, on a display system, an image that is reflective ofa view from a current location of the platform; processing the terraindata and the aircraft state data to (i) identify a water feature, and(ii) determine a textural representation comprising a symbol arranged inan associated symbol pattern, for the water feature; and texturizing thewater feature by overlaying, on the image, the water feature with thetextural representation, thereby repeating the symbol and symbol patternthroughout the water feature.
 2. The method of claim 1, wherein thesymbol pattern of the textural representation comprises dimensions thatare responsive to a distance between the platform and the water feature.3. The method of claim 2, further comprising adjusting symbol dimensionsin accordance with the symbol pattern dimensions.
 4. The method of claim3, further comprising determining the textural representation based on acomparison of a threshold range and the distance between the platformand the water feature.
 5. The method of claim 4, further comprisingdetermining that the distance between the platform and the water featureis greater than the threshold range; and employing a first texturalrepresentation responsive thereto.
 6. The method of claim 5, furthercomprising determining when the distance between the platform and thewater feature is less than or equal to the threshold range; andemploying a second textural representation responsive thereto.
 7. Themethod of claim 1, wherein the symbol or symbol pattern comprisesdimensions that are responsive to water feature dimensions.
 8. A visionsystem, comprising: a navigation system; a display system; a terraindatabase; and a control module operationally coupled to the navigationsystem, the display system, and the terrain database, the control moduleconfigured to: receive terrain data from the terrain database; receiveaircraft state data from the navigation system; display, on the displaysystem, a map image that is reflective of a view from a current locationof the platform; process the terrain data and the aircraft state data to(i) identify a water feature, and (ii) determine a texturalrepresentation comprising a symbol arranged in an associated symbolpattern for the water feature; and texturize the water feature byoverlaying, on the map image, the water feature with the texturalrepresentation, thereby repeating the symbol and symbol patternthroughout the water feature.
 9. The system of claim 8, wherein thesymbol pattern comprises dimensions that are responsive to a distancebetween the platform and the water feature.
 10. The system of claim 9,wherein the symbol pattern dimensions are additionally responsive towater feature dimensions.
 11. The system of claim 10, wherein thecontrol module is further configured to adjust symbol dimensions inaccordance with the symbol pattern dimensions.
 12. The system of claim8, wherein the control module is further configured to determine thetextural representation based on a comparison of a threshold range and adistance between the platform and the water feature.
 13. The system ofclaim 12, wherein the control module is further configured to: determinethat the distance between the platform and the water feature is greaterthan the threshold range; and employ a first textural representationresponsive thereto.
 14. The system of claim 13, wherein the controlmodule is further configured to: determine when the distance between theplatform and the water feature is less than or equal to the thresholdrange; and employ a second textural representation responsive thereto.15. A control module for use in a combined vision system (CVS) on anaircraft having a navigation system, the control module comprising: amemory comprising terrain data; and a processor operationally coupled tothe memory and configured to process terrain data and aircraft statedata to: generate display commands for a display system to generate amap image that is reflective of a view from a current location of theaircraft; identify a water feature; and determine a texturalrepresentation for the water feature comprising a symbol repeatedthroughout the water feature that is plainly visible and distinguishablewhen overlaid on a synthetic vision system (SVS) map image that employscoloration techniques.
 16. The control module of claim 15, wherein theprocessor is further configured to generate commands for the displaysystem to texturize the water feature by overlaying, on the map image,the water feature with the textural representation.
 17. The controlmodule of claim 16, wherein the textural representation comprisesrepeating the symbol in an associated symbol pattern, and wherein thesymbol pattern comprises dimensions that are responsive to a distancebetween the aircraft and the water feature.
 18. The control module ofclaim 17, wherein the processor is further configured to determine thetextural representation based on a comparison of a threshold range anddistance between the aircraft and the water feature.